Antibody chips in which antibody is immobilized are utilized for detecting infection such as hepatitis C and the flu, or environmental pollutant in food. (Refer to Patent Literature 1, for example.) For example, by utilizing antibody chips, it is possible to determine rapidly whether the flu is H1N1, Hong Kong type, a new type, or the like.
As an antibody chip, a microplate with a plurality of cups in which antibody is immobilized is generally used. If a specimen to be examined has an antigen, the antigen brings about an antigen antibody reaction with the antibody immobilized in the cup and the specimen is determined as positive by the examination.
Referring to FIG. 9, a cup 105 of a conventional antibody chip in which antibody is immobilized will be described. FIG. 9 illustrates a cross-section view of the cup 105 of a conventional antibody chip. Generally, antibody cannot be bound directly to a plastic cup 105. Thus, antibody has been immobilized in the cup 105 by stacking activation layer 115, immobilization layer 113, coupling layer 111 and antibody layer 109 successively to the cup 105.